Files
linux/tools/testing/selftests/bpf/progs/preempt_lock.c
Kumar Kartikeya Dwivedi d402755ced bpf: Unify resource leak checks
There are similar checks for covering locks, references, RCU read
sections and preempt_disable sections in 3 places in the verifer, i.e.
for tail calls, bpf_ld_[abs, ind], and exit path (for BPF_EXIT and
bpf_throw). Unify all of these into a common check_resource_leak
function to avoid code duplication.

Also update the error strings in selftests to the new ones in the same
change to ensure clean bisection.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20241103225940.1408302-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-11-03 16:52:06 -08:00

133 lines
2.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <vmlinux.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
#include "bpf_misc.h"
#include "bpf_experimental.h"
SEC("?tc")
__failure __msg("BPF_EXIT instruction cannot be used inside bpf_preempt_disable-ed region")
int preempt_lock_missing_1(struct __sk_buff *ctx)
{
bpf_preempt_disable();
return 0;
}
SEC("?tc")
__failure __msg("BPF_EXIT instruction cannot be used inside bpf_preempt_disable-ed region")
int preempt_lock_missing_2(struct __sk_buff *ctx)
{
bpf_preempt_disable();
bpf_preempt_disable();
return 0;
}
SEC("?tc")
__failure __msg("BPF_EXIT instruction cannot be used inside bpf_preempt_disable-ed region")
int preempt_lock_missing_3(struct __sk_buff *ctx)
{
bpf_preempt_disable();
bpf_preempt_disable();
bpf_preempt_disable();
return 0;
}
SEC("?tc")
__failure __msg("BPF_EXIT instruction cannot be used inside bpf_preempt_disable-ed region")
int preempt_lock_missing_3_minus_2(struct __sk_buff *ctx)
{
bpf_preempt_disable();
bpf_preempt_disable();
bpf_preempt_disable();
bpf_preempt_enable();
bpf_preempt_enable();
return 0;
}
static __noinline void preempt_disable(void)
{
bpf_preempt_disable();
}
static __noinline void preempt_enable(void)
{
bpf_preempt_enable();
}
SEC("?tc")
__failure __msg("BPF_EXIT instruction cannot be used inside bpf_preempt_disable-ed region")
int preempt_lock_missing_1_subprog(struct __sk_buff *ctx)
{
preempt_disable();
return 0;
}
SEC("?tc")
__failure __msg("BPF_EXIT instruction cannot be used inside bpf_preempt_disable-ed region")
int preempt_lock_missing_2_subprog(struct __sk_buff *ctx)
{
preempt_disable();
preempt_disable();
return 0;
}
SEC("?tc")
__failure __msg("BPF_EXIT instruction cannot be used inside bpf_preempt_disable-ed region")
int preempt_lock_missing_2_minus_1_subprog(struct __sk_buff *ctx)
{
preempt_disable();
preempt_disable();
preempt_enable();
return 0;
}
static __noinline void preempt_balance_subprog(void)
{
preempt_disable();
preempt_enable();
}
SEC("?tc")
__success int preempt_balance(struct __sk_buff *ctx)
{
bpf_guard_preempt();
return 0;
}
SEC("?tc")
__success int preempt_balance_subprog_test(struct __sk_buff *ctx)
{
preempt_balance_subprog();
return 0;
}
SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")
__failure __msg("sleepable helper bpf_copy_from_user#")
int preempt_sleepable_helper(void *ctx)
{
u32 data;
bpf_preempt_disable();
bpf_copy_from_user(&data, sizeof(data), NULL);
bpf_preempt_enable();
return 0;
}
int __noinline preempt_global_subprog(void)
{
preempt_balance_subprog();
return 0;
}
SEC("?tc")
__failure __msg("global function calls are not allowed with preemption disabled")
int preempt_global_subprog_test(struct __sk_buff *ctx)
{
preempt_disable();
preempt_global_subprog();
preempt_enable();
return 0;
}
char _license[] SEC("license") = "GPL";